fd_server: use RwLock instead of Mutex

`nix::dir::Dir` isn't Sync (required by `RwLock`), so I had to replace
it with `OwnedFd`.

Bug: 220386264
Test: atest AuthFsHostTest
Test: performance change before vs after is hard to tell
Change-Id: Ib3fd9047970a856b532234f0bebad652172e12de
3 files changed
tree: ac677158fdbec1660d230ba7858ce3018fa49a7f
  1. .prebuilt_info/
  2. apex/
  3. apkdmverity/
  4. authfs/
  5. compos/
  6. demo/
  7. docs/
  8. javalib/
  9. launcher/
  10. libs/
  11. microdroid/
  12. microdroid_manager/
  13. pvmfw/
  14. tests/
  15. virtualizationservice/
  16. vm/
  17. zipfuse/
  18. .clang-format
  19. .gitignore
  20. Android.bp
  21. OWNERS
  22. PREUPLOAD.cfg
  23. README.md
  24. TEST_MAPPING
README.md

Virtualization

This repository contains userspace services related to running virtual machines on Android, especially protected virtual machines. See the getting started documentation and Microdroid README for more information.